How do implantable loop recorders work?

What does an implantable loop recorder do?

Sometimes people have symptoms such as palpitations, dizzy spells or blackouts, that are worrying but only happen occasionally. When this happens, standard heart rhythm monitoring for 24 or 48 hours may not help if you don’t have symptoms during the recording period. An implantable loop recorder (ILR) monitors your heart rate and rhythm continuously and stores them in its memory. 

What does an implantable loop recorder look like?

An implantable loop recorder is a small, rectangular-shaped device that looks a bit like a USB stick (a memory stick for your computer) or a small pack of chewing gum. The more recent models are even smaller: they look like a very thick matchstick. Depending on how recent the model is, they are about 1–2 inches (2.5–5 centimetres) long. They are made of a metal casing, a battery and an electrical circuit inside.

How does an implantable loop recorder work?

The loop recorder makes a recording of your heart rhythm if it detects that your heart is beating abnormally, or if you use the hand-held activator (below) that comes with it. When you experience symptoms, you can place the activator over the implantable loop recorder and press a button that tells the device to make a recording. Usually it can capture a recording starting a few minutes before, so don’t worry if the symptoms stop when you press the button.

How is an implantable loop recorder fitted?

You are given an injection of local anaesthetic to numb the area. A small cut (as little as half a centimetre or a quarter of an inch) is made on the left of your chest and the implantable loop recorder is inserted under the skin. The wound is typically closed with a special type of glue; however, sometimes a couple of stitches or steri-strips (paper stitches) are used. The procedure takes about 10 to 15 minutes. You won’t need to go without food or drink beforehand.

The implantable loop recorder sits in the left of your chest and is inserted just underneath the skin.

What are the risks?

As with any invasive procedure, there are risks of infection or bleeding, but these risks are very low.

What is the recovery like?

You may feel a bit bruised and sore where the skin is cut, but this will get better quickly. As long as you feel well, you can go home and get on with your day as normal. Longer term, you might be able to feel it but it shouldn’t hurt.

How long do you have an implantable loop recorder for?

Usually until it helps make a diagnosis or the battery runs out (up to three years). However, the implantable loop recorder can be taken out at any time if the patient or medical team wish. If the implantable loop recorder shows that you need a pacemaker, it can be removed at the same time that the pacemaker is put in.

Will I get the results immediately?

The implantable loop recorder sends recordings electronically to your medical team to review. You will probably be given a small electronic transmitter (below) to keep at home.

Depending on your device, the results are either sent automatically to your medical team using the bedside monitor, or you might be asked to attend a hospital clinic where the cardiac physiologists download the results from your implantable loop recorder. This is completely non-invasive: the implantable loop recorder doesn’t need to be removed. You will be told which of these you need to do.

How is an implantable loop recorder taken out?

It’s removed the same way it was put in: a small incision is made along the original scar, using local anaesthetic.

Can I do things I normally do, like go to the gym, while I have one?

It is fine for you to go about your day-to-day life straight away. If you feel any symptoms or palpitations, you can use the hand-held activator if you have it with you, and make a note of where and when it happened and what you were doing at the time, to discuss with your doctor when you get the results through.

The implantable loop recorder shouldn’t restrict your normal life. You can go through security scanners safely, although you may set off metal detectors – show your device identification card if this happens. In most cases you can take it abroad if you are going on holiday. Ask your specialist for detailed advice.